This invention relates to polyphosphazene polymers containing repeating ##STR3## units in the polymer chain in which substituents derived from thienyl alcohols are attached to the phosphorus atom. More particularly, the invention relates to homopolymers containing substituents having the structure: ##STR4## (defined hereinafter) and to copolymers containing such substituents along with other compatible substituents.
Polyphosphazene polymers containing repeating ##STR5## units in which various alkoxy, substituted alkoxy, aryloxy, substituted aryloxy, amino and mercapto groups are attached to the phosphorus atom and their method of preparation are described in the prior art as illustrated in the publication "Phosphorus-Nitrogen Compounds", Academic Press, New York, New York, 1972 by H. R. Allcock and "Poly(Organophosphazenes)", Chemtech, Sept. 19, 1975 by H. R. Allcock and in such U.S. Pat. Nos. as 3,515,688; 3,702,833; 3,856,712; 3,974,242 and 4,042,561, the disclosures of which are incorporated herein by reference.
In addition, polyphosphazene copolymers containing small amounts of monoethylenically unsaturated substituents which are capable of undergoing further reaction (i.e. crosslinking) at temperatures ranging from 200.degree. to 350.degree. F. are known in the prior art as illustrated by U.S. Pat. Nos. 3,702,833; 3,844,983; 3,888,799 and 4,055,520. As described in the aforementioned patents, these reactive unsaturated substituents may be unsaturated monovalent radicals such as ##STR6## where R is an aliphatic or aromatic radical.
The polymers described in the above patents exhibit a number of advantageous properties as a result of the inclusion of small amounts of the above described unsaturated substituents therein. Thus, such polymers where crosslinked are often useful as solvent and chemically resistant coatings, sealants, potting compounds and the like.
However, as indicated, polymers containing such unsaturated substituents generally require elevated temperatures in the range of 200.degree. to 350.degree. F. to affect crosslinking. In contrast, the polymers of this invention can be cured or crosslinked at ambient temperatures with curing agents such as salts of bi- or -polyvalent metals. Especially advantageous metallic salts of this type are metallic halides.